Applicability of 2NN-MEAM potentials in the prediction of temperature and oxygen-dependent elastic properties of titanium

A second nearest neighbour (2NN) modified embedded atom method (MEAM) potential was recently derived by Joost et al. (2015) for Ti–O. Transferability of the potential was demonstrated by those authors through zero temperature molecular statics modelling of various phases of Ti–O not included in the original set of fitting parameters. In the study presented here, the Ti–O potential is tested over a temperature range from 300K to 700K by comparing elastic properties against experimental data, in order to assess its transferability to high temperature behaviour. It is found that the Ti–O MEAM accurately predicts the hcp titanium Youngʼs modulus as a function of oxygen content at room temperature. At higher temperatures, however, the simulated Youngʼs modulus over predicts the experimentally determined response. It is further shown that the inaccuracies in Ti–O MEAM potential predictions are directly related to the inability of the Ti MEAM potential to predict the temperature dependence of the shear modulus of hcp titanium above 300K.